Independently operating multi-stage governor



J- J. DUFFY March 22, 1966 INDEPENDENTLY OPERATING MULTI-S'I'AGE GOVERNOR Filed Dec. 28, 1962 I N VEN TOR. 3%

JAMES J. DUFFK United States Patent 3,241,565 INDEPENDENTLY OPERATING MULTI-STAGE GOVERNOR James J. Duffy, Livonia, Mich, assignor to Ford Motor Company, Dearborn, Micln, a corporation of Delaware Filed Dec. 28, 1962, Ser. No. 248,120 8 Claims. (Cl. 13754) v This invention relates to a fluid pressure governor system, and more particularly to a centrifugal fluid pressure governor of the multi-stage or break-point type providing two governor signal pressure levels that vary as a function of the speed of rotation of the governor.

Multi-stage fluid pressure governors of the centrifugal type generally utilize a number of valve elements individually mounted within a valve body and slidable in response to the movement of centrifugally actuated weights to provide different governor signal pressures. The use of valve elements operating within valve bodies not only renders the governor more complex, but also increases the maximum radius of the overall construction. Also, a separate fluid supply to each of the valve elements is generally required. As a result, the known constructions of this type of governor are generally expensive to manufacture and repair.

This invention provides a simplified and economical governor construction providing a number of different fluid signal pressure levels. The invention utilizes centrifugal weight members symmetrically disposed on pposite sides of a shaft with which they rotate, the weights serving also as valve members to modulate the pressure flowing through a number of discharge ports in a rotating body. No counterweight or separate valve elements are necessary, the modulated governor pressure being obtained simply by the movement of the weights in response to the differential between the centrifugal force acting on the weight in one direction opposed by the modulated fluid pressure in the discharge ports acting on the weights in the opposite direction. Thus, a centrifugal fluid pressure governor is provided having a minimum overall radius and a single feed with no valve elements other than the centrifugal weights themselves.

It is therefore an object of the invention to provide a fluid pressure governor system that is simple in construction and economical to manufacture.

It is also an object of the invention to provide a centrifugal fluid pressure governor construction affording a plurality of governor signal pressure levels varying as a function of the speed of rotation of the governor.

It is a still further object of the invention to provide a two-stage centrifugal fluid pressure governor construction comprising a longitudinally extending body rotatable with a shaft at right angles thereto, the body having fluid discharge ports at opposite ends connected to a source of fluid, the discharge being controlled by centrifugal weight members slidably mounted to move across the ports to regulate the pressure of the fluid therein as a function of the differential between the centrifugal force and the modulated pressure in the discharge ports acting on the weights. The invention also has for an object to provide a stepped-type governor such that a fast rise in pressure is obtained at low speeds of rotation, while a slow rise is obtained thereafter, this being accomplished by maintaining one of the centrifugal weight valve members in a nonregulating position so long as the other centrifugal weight valve is modulating the fluid pressure in the discharge ports.

It is a still further object of the invention to provide a fluid pressure governor system wherein flow restriction means are provided in a conduit connecting a source of fluid under pressure to a centrifugal fluid pressure goverice nor, the governor being of the construction described to provide a signal pressure in the conduit downstream of the restricting means that varies as a function of the square of the speed of rotation of the governor.

Other objects, features and advantages of the invention will become apparent upon reference to the succeeding, detailed description thereof, and to the drawing illustrating the preferred embodiment thereof; wherein,

FIGURE 1 is a schematic illustration of a portion of a fluid pressure governor system embodying the invention,

FIGURE 2 is an enlarged, detailed cross sectional view of the two-stage governor of FIGURE 1, taken on a plane indicated by and viewed in the direction of the arrows 22 of FIGURE 1, and

FIGURE 3 is a graph plotting pressure versus speed to illustrate the different signal pressure levels provided by the governor constructed in accordance with the invention.

FIGURE 1 shows a fluid pressure supply system for a centrifugal governor 10. It consists of a fluid pump 12 preferably driven by the transmission output shaft of a motor vehicle so as to provide an output pressure varying in accordance with the speed of the vehicle. The pump may be of a known variable capacity type having an inlet 14 supplied with fluid from a sump 16, and an outlet line 18 connected to the inlet of the governor 10. Line 18 is provided with an orifice 20 effecting a pressure differential between the upstream and downstream sides 22 and 24 and permitting a pressure buildup in a branch line 26 supplying fluid to a fluid pressure controlling device or other devices (not shown). The downstream side 24 has a branch 28 leading to fluid pressure devices, such as, for example, the shift valves of an automatic transmission control system adapted to be actuated by a governor signal pressure so as to have a movement indicative of the change in vehicle speed.

The governor 10, FIGURES 1 and 2, is of the twostage or break-point type giving a fast rise in pressure at low rotational speeds and a slow rise thereafter. It operates on a regulated flow principle being fed from the single pressure source 12 through the orifice 20 to provide a signal pressure in line 28 varying as the function of the square of the speed of rotation.

The governor has a longitudinally extending main body portion 32 fixed to a power output shaft 30 and extending laterally from the shaft in opposite directions. One end of the body has a stepped enlargement 34 consisting of two different diameter bosses or lands 36 and 38 with an annular fluid recess or port 40 between. Along its axis, the body has a main fluid supply bore 42 open at all times to supply conduit 18 by means of an intersecting bore 44. The bore 42 is closed at one end by a plug 46, and is further intersected at this end by a cross bore 48 connecting the fluid from pressure line 18 to the annular recess 40.

A centrifugal weight 50 of a calibrated mass and shape is slidably and sealingly mounted for a radial movement on enlargement 34, and rotates with it. The weight is provided with an annular notch or groove 52 having radial and axial dimensions as shown to sealingly cover recess 40 in the position illustrated. The weight has a tapered cutout at 54 to permit venting of some of the fluid in recess 40 to a sump (not shown) when the weight moves to the right from the position shown in FIGURE 2. The tapered surface provides a knife edge contact of the weight with the edge 55 of boss 36 to prevent leakage of fluid past this point when the port 40 is closed. Thus, it will be seen that the radial face 56 constitutes a differential area against which the fluid under pressure in recess 40 acts to move the weight radially inwardly and opposite to the normal outward movement of weight 50 by centrifugal force.

This portion of the governor constitutes the first stage of regulation of the fluid pressure in line 28. In operation, the weight doubles as a sleeve valve to modulate the pressure of the fluid in port 40. More specifically, the initial rotation of output shaft rotates body 32 and Weight 50 effecting a centrifugal force on the rotating mass of the weight to move it radially to the position shown closing port 40. Simultaneously, the output shaft rotates pump 12 to supply fluid to line 18, whereupon it is bled through orifice 20 to flow through bores 44, 4-2 and 48 to port 40. Port being closed permits a pressure buildup against the area of face 56 of the weight until such time as it exceeds the increasing centrifugal force holding the weight in a port closing position. At this time, the weight moves inwardly, opening port 40 just enough to exhaust a small quantity of fluid through vent 54, this quantity being that necessary to lower the pressure in port 40 to a point Where the fluid pressure force against weight 50 is equal to the centrifugal force for the specific speed of rotation. Upon continued rise in rotational speed, the weight again moves to close down the communication between port 40 and vent 54. This process is repeated for each change in the speed of body 32, the weight valve member each time seeking an equilibrium position whereby the centrifugal force is balanced by the fluid pressure acting on the weight. Since the centrifugal force varies as the square of the speed of rotation and the radial distance of the weights from the axis of rotation, this regulating action of the weight, therefore, produces a governor signal pressure in line 28 that changes also as a function of the speed of rotation of the governor. The mass and shape of the Weight and port and bore sizes are so calibrated that the action of this first stage governor portion provides a fast rise in pressure in line 28 at low r.p.m.s of shaft 30. This is indicated by the line 56 in the graph in FIGURE 3.

A second stage governor portion providing a slow rise in governor signal pressure at higher speeds of rotation of shaft 30 is secured to the opposite end of body 32. It includes a sleeve 62 secured to main body 32 by pins 64, the sleeve having an annular flange 61. The sleeve and flange are surrounded by a centrifugal weight 68 having a radially sliding but sealed fit on the body portion 32, and rotates with it. The weight is shaped with an annular recess 70 of a diameter comparable to that of the edge of flange 61, and as with weight 50, has a tapered cutout 72 that not only vent fluid in recess 70 to a sump, but provides a knife-edge unit sealing contact of flange 66 with the Weight. The recess or port 70 is supplied with fluid from main bore 42 through an intersecting bore 74. The weight additionally has an annular pocket 76 in which is seated a compression spring 78. The opposite end of the spring is seated against a flat 8t machined on the shaft 30, and biases weight 68 against flange 66 to close or cover the recess 70.

It will be noted that the large lateral extent of flange 61 provides the recess 70 with a correspondingly large face area 82 against which the fluid under pressure acts in an attempt to open communication between the recess and vent 72. To provide the break-point operation desired, this stage of the governor does no regulating below a predetermined speed of rotation of shaft 30, i.e., it does no regulating as long as the first stage is operable. Therefore, the force of spring 78 and the mass and shape of weight 68 and size of recess '70 and the ports are so calibrated that the changing centrifugal force on the Weight plus the spring force are overcome by the force of the rising fluid pressure against face 82 to move the weight to a regulating position only after the first stage weight 50 has moved to completely close port 40, i.e., at substantially the moment the first stage of regulation of fluid pressure has been terminated.

Thereafter, with continued increase in speed of shaft 30, the weight 68 moves radially outwardly to a regulating position alternately restricting and opening the communication between races 70 and vent 72 in accordance with the change in centrifugal and fluid pressure forces on the weight to provide a slowly changing fluid pressure in bore 42 and governor signal pressure line 28 that varies as a function of the speed of shaft 30. This change in the second stage governor signal pressure is indicated by the line 84 in FIGURE 3.

Thus, it will be seen that the governor of this invention provides two stages of a governor signal pressure, i.e., low rotational speeds of the output shaft providing a fast changing pressure of regulation of the fluid pressure by weight valve member 50, with higher rotational speeds of shaft 30 providing a slowly changing governor signal pressure by regulation of the fluid by weight valve member 68. It will also be seen that while either regulating stage is operable, the other stage is inoperable, and that both stages have a common feed line.

While the invention has been illustrated in its preferred form in the figure, it will be clear to those skilled in the art to which the invention pertains that many changes and modifications may be made thereto without without departing from the scope of the invention.

I-clairn:

1. A multi-stage centrifugal governor comprising a rotatable shaft having portions extending laterally thereof, a source of fluid, said portions each having a fluid discharge port adjacent the outer end thereof connected to said source, and a centrifugal weight member slidably mounted on each portion adjacent said port for movement across said port to independently regulate the fluid discharge from the port associated with said member and modulate the fluid pressure in said port in response to the differential between centrifugal force opposed by the pressure of the regulated fluid in said port acting on said weight member, the pressure of the fluid in said ports varying as a function of the speed of rotation of said shaft and the mass of the weight member associated with said port, and means for preventing the modulating movement of one of said weight members while the other of said weight members is modulating the fluid pressure.

2. A multi-stage centrifugal governor comprising a rotatable shaft having portions extending from opposite lateral sides thereof, a source of fluid, said portions each having a fluid discharge port adjacent its outer end connected to said source, a centrifugal weight slidably mounted on each of said ends adjacent said port and movable to independently regulate the fluid discharge from said port in response to the differential between centrifugal force acting on the weight associated therewith opposed by the pressure of regulated fluid in said ports acting on said weight, the pressure of the fluid in said ports varying as a function of the change in speed of rotation of said shaft, and means biasing one of said weights to a nonregulating position below a predetermined pressure of the regulated fluid in said ports.

3. A multi-stage centrifugal governor comprising a rotatable shaft having a single body extending across the axis of said shaft, a source of fluid, said body having a fluid discharge port adjacent opposite ends thereof, conduit means connecting each of said ports to each other and to said source, a centrifugal weight slidably mounted on said body adjacent each of said ports and movable to independently regulate the fluid discharge from said port associated therewith in response to the differential between centrifugal force acting on said weight opposed by the pressure of regulated fluid in said ports acting on said weights, the pressure of the fluid in said ports varying as a function of the change in speed of rotation of said shaft, and means biasing one of said weights to a nonregulating position below a predetermined pressure of the regulated fluid in said ports, the attainment of said predetermined pressure biasing said other weight to a nonregulating position.

4. A fluid pressure governor system comprising, in combination, a source of fluid under pressure, a centrifugal governor rotatable with a shaft, conduit means connecting said source and said governor, fluid restriction means in said conduit means providing a differential in pressure between upstream and downstream sides thereof, said governor regulating the pressure in said downstream side as a function of the speed of rotation of said shaft, said governor comprising a body rotatable with said shaft and having portions extending laterally from the axis thereof, said portions each having a fluid discharge port connected to the fluid in said conduit means at the downstream side of said restriction means, and a centrifugal weight slidably mounted on each of said body portions for movement across the port associated therewith to independently regulate the fluid discharge therefrom in response to the differential between centrifugal force and the pressure of regulated fluid in said port acting on said weight.

5. A fluid pressure governor system comprising, a source of fluid under presure, a multi-stage fluid pressure centrifugal governor rotatable with a shaft, conduit means connecting said source and said governor, fluid restriction means in said conduit means providing a differential in pressure between upstream and downstream sides thereof, said governor regulating the pressure in said downstream side as a function of the speed of rotation of said shaft, said governor comprising a body extending laterally in opposite directions from and rotatable with said shaft and having a fluid discharge port at opposite ends, means connecting each of said ports to said conduit means on the downstream side of said restriction means, a centrifugal weight slidably mounted on said body adjacent each of the port associated therewith for movement to independently regulate the fluid discharge from said ports in response to the differential between centrifugal force and the pressure of regulated fluid in said port acting on the adjacent weight, and means preventing a regulating movement of one of said weights until the other of said weights has moved to a nonregulating position.

6. A fluid pressure governor system comprising, a source of fluid under presure, a centrifugal governor rotatable with a shaft, conduit means connecting said source and said governor, fluid restriction means in said conduit means providing a differential in pressure between upstream and downstream sides thereof, said governor regulating the pressure in said downstream side as a function of the speed of rotation of said shaft, said governor comprising a body extending transversely across said shaft and having a fluid discharge port adjacent opposite ends thereof, means connecting said ports to each other and to said conduit means on the downstream side of said restriction means, and a centrifugal weight slidably mounted on said body adjacent each of said ports for independent movement across said port to independently regulate the discharge therefrom in response to the differential between centrifugal force and the pressure of regulated fluid in said port acting on the weight associated therewith, and means moving one of said weights to an inoperative regulating position While the other of said weights is regulating.

'7. A governor as described in claim 3, said weights each having a tapered portion adjacent to and cooperating with the port associated therewith, said tapered portion providing a sharp edge port closing portion on said weight.

8. A governor as described in claim 6, said weights each having a tapered portion adjacent to and cooperating with the port associated therewith, said tapered portion providing a sharp edge port closing portion on said weight.

References Cited by the Examiner UNITED STATES PATENTS 1,329,385 2/1920 Egger 137-56 X 1,347,208 7/1920 Cockburn 13756 2,711,749 6/1955 Hettinger 137-56 2,889,844- 6/1959 McFarland 137-56 X 3,086,541 4/1963 De Corte 137-56 FOREIGN PATENTS 618,652 4/1961 Canada. 790,618 2/ 1958 Great Britain.

ISADOR WEIL, Primary Examiner.

CLARENCE C. GORDON, Examiner. 

1. A MULTI-STAGE CENTRIFUGAL GOVERNOR COMPRISING A ROTATABLE SHAFT HAVING PORTIONS EXTENDING LATERALLY THEREOF, A SOURCE OF FLUID, SAID PORTIONS EACH HAVING A FLUID DISCHARGE PORT ADJACENT THE OUTER END THEREOF CONNECTED TO SAID SOURCE, AND A CENTRIGUGAL WEIGHT MEMBER SLIDABLY MOUNTED ON EACH PORTION ADJACENT SAID PORT FOR MOVEMENT ACROSS SAID PORT TO INDEPENDENTLY REGULATE THE FLUID DISCHARGE FROM THE PORT ASSOCIATED WITH SAID MEMBER AND MODULATE THE FLUID PRESSURE IN SAID PORT IN RESPONSE TO THE DIFFERENTIAL BETWEEN CENTRIFUGAL FORCE OPPOSED BY THE PRESSURE OF THE REGULATED FLUID IN SAID PORT ACTING ON SAID WEIGHT MEMBER, THE PRESSURE OF THE FLUID IN SAID PORTS VARYING AS A FUNCTION OF THE SPEED OF ROTATION OF SAID SHAFT AND THE MASS OF THE WEIGHT MEMBER ASSOCIATED WITH SAID PORT, AND MEANS FOR PREVENTING THE MODULATING MOVEMENT OF ONE OF SAID WEIGHT MEMBERS WHILE THE OTHER OF SAID WEIGHT MEMBERS IN MODULATING THE FLUID PRESSURE. 